发明授权
- 专利标题： Synchronization system for key telephone system
- 专利标题（中）： 关键电话系统同步系统
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申请号： US151733申请日： 1980-05-20
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公开(公告)号： US4314109A公开(公告)日： 1982-02-02
- 发明人: Koichi Sekiguchi , Kazuyuki Yamamoto
- 申请人： Koichi Sekiguchi , Kazuyuki Yamamoto
- 申请人地址： JPX both of JPX both of
- 专利权人： Iwasaki Tsushinki Kabushiki Kaisha,Nippon Telegraph & Telephone Public Corporation
- 当前专利权人： Iwasaki Tsushinki Kabushiki Kaisha,Nippon Telegraph & Telephone Public Corporation
- 当前专利权人地址： JPX both of JPX both of
- 优先权： JPX54-70375 19790605
- 主分类号： H04Q3/58
- IPC分类号： H04Q3/58 ; H04J3/06 ; H04J3/12 ; H04J3/14 ; H04M1/72 ; H04M9/00
摘要：
A synchronization system for a key telephone system, in which key information or the like information signal between a key service unit and each key telephone set is transmitted in the form of a time-division pulse signal under the control of a counter provided in the key service unit. The information signal has a format which is divided into a first signal from the key service unit to each key telephone set and a second signal from each key telephone set to the key service unit so as to make distinction between the first and second signals in terms of time. The first signal is disposed in a time slot preceding the second signal to provide a pair of signal groups. A one-pulse start signal is disposed in the foremost time slot of the signal groups and a one-pulse answer signal is disposed in a time slot between the first signal and the second signal.
公开/授权文献
- US5425337A Pre-chamber type engine 公开/授权日：1995-06-20
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